ABSTRACT
The CXCR4 receptor and its ligand CXCL12 (also named stromal cell-derived factor 1, SDF1) have a critical role in chemotaxis and homing, key steps in cancer metastasis. Although myofibroblasts expressing CXCL12 are associated with the presence of axillary metastases in HER2 breast cancers (BC), the therapeutic interest of targeting CXCR4/CXCL12 axis in the different BC subtypes remains unclear. Here, we investigate this question by testing antitumor activity of CXCR4 inhibitors in patient-derived xenografts (PDX), which faithfully reproduce human tumor properties. We observed that two CXCR4 inhibitors, AMD3100 and TN14003, efficiently impair tumor growth and metastasis dissemination in both Herceptin-sensitive and Herceptin-resistant HER2 BC. Conversely, blocking CXCR4/CXCL12 pathway in triple-negative (TN) BC does not reduce tumor growth, and can even increase metastatic spread. Moreover, although CXCR4 inhibitors significantly reduce myofibroblast content in all BC subtypes, they decrease angiogenesis only in HER2 BC. Thus, our findings suggest that targeting CXCR4 could provide some therapeutic interest for HER2 BC patients, whereas it has no impact or could even be detrimental for TN BC patients.
Subject(s)
Breast Neoplasms/drug therapy , Heterocyclic Compounds/pharmacology , Lung Neoplasms/secondary , Neovascularization, Pathologic/drug therapy , Peptides/pharmacology , Receptor, ErbB-2/metabolism , Receptors, CXCR4/antagonists & inhibitors , Triple Negative Breast Neoplasms/pathology , Animals , Anti-HIV Agents/pharmacology , Apoptosis/drug effects , Benzylamines , Biomarkers, Tumor/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Cyclams , Female , Gene Expression Regulation, Neoplastic/drug effects , Humans , Lung Neoplasms/drug therapy , Lung Neoplasms/metabolism , Mice , Neoplasm Invasiveness , Signal Transduction , Triple Negative Breast Neoplasms/drug therapy , Triple Negative Breast Neoplasms/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
The aim of the study was to investigate the renal function in clinically normal dogs receiving meloxicam and pimobendan alone or in combination. Ten adult female beagle dogs were administered the treatment for 7 days in a randomized crossover trial (control/meloxicam/pimobendan/meloxicam and pimobendan). Renal function was assessed by blood urea, creatinine, sodium, potassium and chloride concentrations and by glomerular filtration rate, measured by means of renal scintigraphy [renal uptake of (99m)Tc-diethylenetriaminepentacetic acid (DTPA)] and plasma clearance of (99m)Tc-DTPA. As compared with the control group, renal uptake and plasma clearance of (99m)Tc-DTPA were not significantly modified after a 7-day period of treatment with meloxicam or pimobendan alone, or meloxicam and pimobendan in combination. Furthermore, urea, creatinine, sodium, potassium and chloride levels in the serum of the dogs during the 7-day period treatment were not significantly modified in relation to the treatments. It was therefore concluded that meloxicam and pimobendan alone or in combination did not alter renal function in healthy dogs.